This invention is directed to a ruffler attachment for a sewing machine, and in particular to a ruffler attachment for a sewing machine, which attachment is coupled to the main drive of a sewing machine and is operated in synchronism with the sewing machine thereby. While ruffler attachments for sewing machines have taken on various forms, the difficulties encountered in synchronizing the operation of the ruffler attachment with the sewing operation of the machine, and the difficulties in altering or redesigning the sewing machine to add such ruffler attachments has rendered same less than completely satisfactory. Specifically, the difficulties in effecting the necessary synchronization between the ruffle forming apparatus, wherein a trim fabric is pleated and sewn to a body fabric, with the sewing operation of the sewing machine has rendered the adjustment in size of the ruffle formed in the trim fabric, and the number of ruffles to be formed over a predetermined length of body fabric to require extensive, time-consuming and otherwise expensive adjustments to the sewing machine and ruffler attachment mechanisms.